Temperature control in a space served by multiple HVAC equipment

Abstract

A system and method for regulating the operation of first and second temperature modification sources for heating or cooling a building structure is provided. The system switches between the first and second temperature modification sources based on conditions other than just outside temperature.

1. A method for controlling an environmental control system that services an inside space of a building, the environmental control system having a first temperature modification source and a second temperature modification source, both for modifying the temperature of the inside space of the building, the environmental control system further having a temperature set point, the method comprising:
 disabling the second temperature modification source; 
 activating the first temperature modification source; 
 determining if the temperature of the inside space of the building is not reaching the temperature set point within a selected period of time, and if so: 
 disabling the first temperature modification source; 
 at least selectively activating the second temperature modification source; 
 measuring the outside temperature; and 
 determining if the outside temperature has changed by a predetermined amount, and if so: 
 disabling the second temperature modification source and at least selectively activating the first temperature modification source. 
 
     
     
       2. A method for controlling an environmental control system that services an inside space of a building, the environmental control system having a first temperature modification source and a second temperature modification source, both for modifying the temperature of the inside space of the building, the environmental control system further having a temperature set point, the method comprising:
 disabling the second temperature modification source; 
 activating the first temperature modification source; 
 determining if the temperature of the inside space of the building is not reaching the temperature set point within a selected period of time, and if so: 
 disabling the first temperature modification source; and 
 at least selectively activating the second temperature modification source; 
 after the second temperature modification source is at least selectively activated, determining if/when the temperature of the inside space of the building has a predetermined relationship with the temperature set point, and if so: 
 disabling the second temperature modification source; and 
 at least selectively activating the first temperature modification source. 
 
     
     
       3. The method of  claim 2 , wherein the second temperature modification source modifies the temperature of the inside space more rapidly than the first temperature modification source, at least under current operation conditions. 
     
     
       4. The method of  claim 2 , wherein the second temperature modification source is less efficient to operate than the first temperature modification source under current operation conditions. 
     
     
       5. The method of  claim 2  further comprising the step of:
 waiting a selected period of time after the temperature of the inside space of the building has a predetermined relationship with the temperature set point before disabling the second temperature modification source and at least selectively activating the first temperature modification source. 
 
     
     
       6. The method of  claim 2  comprising the steps of:
 receiving a call for heat; 
 activating the first temperature modification source to satisfy the call for heat; 
 determining if the first temperature modification source is able to satisfy the call for heat within the selected period of time, and if not; 
 disabling the first temperature modification source; 
 activating the second temperature modification source to satisfy the call for heat; 
 disabling the second temperature modification source after the call for heat is satisfied; and 
 returning to the receiving a call for heat step. 
 
     
     
       7. The method of  claim 2  comprising the steps of:
 receiving a call for heat; 
 activating the first temperature modification source to satisfy the call for heat; 
 determining if the temperature of the inside space of the building is not moving toward the temperature set point, and if not; 
 disabling the first temperature modification source; 
 activating the second temperature modification source to satisfy the call for heat; 
 disabling the second temperature modification source after the call for heat is satisfied; and 
 returning to the receiving a call for heat step. 
 
     
     
       8. The method of  claim 2  wherein the first temperature modification source is a heat pump. 
     
     
       9. The method of  claim 2  wherein the second temperature modification source is a fuel fired furnace. 
     
     
       10. The method of  claim 2  wherein the second temperature modification source is an electrically powered heater. 
     
     
       11. The method of  claim 2  wherein the second temperature modification source is an electrically powered air conditioner. 
     
     
       12. A method for controlling an environmental control system that services an inside space of a building, the environmental control system having a first temperature modification source and a second temperature modification source, both for modifying the temperature of the inside space of the building, the environmental control system further having a temperature set point, the method comprising:
 receiving a call for heat; 
 activating the first temperature modification source to satisfy the call for heat; 
 determining if the first temperature modification source is able to satisfy the call for heat within a selected period of time, and if not; 
 disabling the first temperature modification source; 
 activating the second temperature modification source to satisfy the call for heat; 
 disabling the second temperature modification source after the call for heat is satisfied; and 
 returning to the receiving a call for heat step. 
 
     
     
       13. The method of  claim 12  wherein the first temperature modification source is a heat pump. 
     
     
       14. The method of  claim 13  wherein the second temperature modification source is a fuel fired furnace. 
     
     
       15. The method of  claim 12  wherein the second temperature modification source is an electrically powered heater. 
     
     
       16. A method for controlling an environmental control system that services an inside space of a building, the environmental control system having a first temperature modification source and a second temperature modification source, both for modifying the temperature of the inside space of the building, the environmental control system further having a temperature set point, the method comprising:
 receiving a call for heat; 
 activating the first temperature modification source to satisfy the call for heat; 
 determining if the temperature of the inside space of the building does not reach the temperature set point within a selected period of time, and if not; 
 disabling the first temperature modification source; 
 activating the second temperature modification source to satisfy the call for heat; 
 disabling the second temperature modification source after the call for heat is satisfied; and 
 returning to the receiving a call for heat step. 
 
     
     
       17. The method of  claim 16  wherein the first temperature modification source is a heat pump. 
     
     
       18. The method of  claim 17  wherein the second temperature modification source is a fuel fired furnace. 
     
     
       19. The method of  claim 17  wherein the second temperature modification source is an electrically powered heater. 
     
     
       20. A controller for controlling an environmental control system that services an inside space of a building, the environmental control system having a first temperature modification source and a second temperature modification source, both for modifying the temperature of the inside space of the building, the environmental control system further having a temperature set point, the controller comprising:
 means for disabling the second temperature modification source; 
 means for at least selectively activating the first temperature modification source; 
 means for determining if the temperature of the inside space of the building is not reaching the temperature set point within a selected period of time, and when so: 
 means for disabling the first temperature modification source; 
 means for at least selectively activating the second temperature modification source; 
 means for determining if/when the temperature of the inside space of the building has a predetermined relationship with the temperature set point after the second temperature modification source is at least selectively activated, and when so: 
 means for disabling the second temperature modification source; and 
 means for at least selectively activating the first temperature modification source. 
 
     
     
       21. A method for controlling an environmental control system that services an inside space of a building, the environmental control system having a first temperature modification source and a second temperature modification source for modifying the temperature of the inside space of the building, the environmental control system further having a temperature set point, the method comprising:
 disabling the second temperature modification source; 
 at least selectively activating the first temperature modification source; 
 determining to activate the second temperature modification source and to disabled the first temperature modification source; 
 disabling the first temperature modification source; 
 at least selectively activating the second temperature modification source; 
 determining a load on the second temperature modification source; 
 determining if/when the load on the second temperature modification source falls below a selected load limit, and if so: 
 disabling the second temperature modification source; and 
 at least selectively activating the first temperature modification source. 
 
     
     
       22. A method for controlling an environmental control system that services an inside space of a building, the environmental control system having a first temperature modification source and a second temperature modification source for modifying the temperature of the inside space of the building, the environmental control system further having a temperature set point, the method comprising:
 disabling the second temperature modification source; 
 at least selectively activating the first temperature modification source; 
 determining a load on the first temperature modification source, and if the load on the first temperature modification source exceeds a selected load level: 
 disabling the first temperature modification source; 
 at least selectively activating the second temperature modification source; 
 determining if/when the load on the second temperature modification source falls below a selected load level, and if so: 
 disabling the second temperature modification source; and 
 at least selectively activating the first temperature modification source. 
 
     
     
       23. The method of  claim 22  wherein the selected load level of the first temperature modification device and the selected load level of the second temperature modification device are based at least in part on one or more operating conditions. 
     
     
       24. The method of  claim 23  wherein the one or more operating conditions include one or more of an outside air temperature, an outside humidity level, an outside wind speed, an outside wind direction, a precipitation value, a time of day value, a time of year value, and a temperature set point for the inside space. 
     
     
       25. A method for controlling an HVAC system that services an inside space of a building, the HVAC system including a heat pump and a fuel fired furnace for modifying the temperature of the inside space of the building, the HVAC system further including a controller and a current temperature set point, the method comprising:
 disabling the fuel fired furnace; 
 at least selectively activating the heat pump; 
 determining if one or more outdoor conditions external to the building fall outside of a selected threshold, and if so: 
 disabling the heat pump; 
 at least selectively activating the fuel fired furnace; 
 waiting a selected period of time, and then: 
 disabling the fuel fired furnace; and 
 at least selectively activating the heat pump. 
 
     
     
       26. A method for controlling an environmental control system that services an inside space of a building, the environmental control system having a first temperature modification source and a second temperature modification source, both for modifying the temperature of the inside space of the building, the environmental control system further having a temperature set point, the method comprising:
 disabling the second temperature modification source; 
 activating the first temperature modification source; 
 determining if the temperature of the inside space of the building is moving away from the temperature set point, and/or not reaching the temperature set point within a selected period of time, and if so: 
 disabling the first temperature modification source; 
 at least selectively activating the second temperature modification source; 
 measuring the outside temperature; 
 determining if the outside temperature has changed by a predetermined amount, and if so: 
 disabling the second temperature modification source and at least selectively activating the first temperature modification source. 
 
     
     
       27. A method for controlling an environmental control system that services an inside space of a building, the environmental control system having a first temperature modification source and a second temperature modification source, both for modifying the temperature of the inside space of the building, the environmental control system further having a temperature set point, the method comprising:
 disabling the second temperature modification source; 
 activating the first temperature modification source; 
 determining if the temperature of the inside space of the building is moving away from the temperature set point, and/or not reaching the temperature set point within a selected period of time, and if so: 
 disabling the first temperature modification source; 
 at least selectively activating the second temperature modification source; 
 after the second temperature modification source is at least selectively activated, determining if/when the temperature of the inside space of the building has a predetermined relationship with the temperature set point, and if so: 
 disabling the second temperature modification source; and 
 at least selectively activating the first temperature modification source.